Driving mechanism



July 19, 1932. H. PFANNENSTIEHL 1,353,366

DRIVING MECHANISM Filed June 25, 1928 2 Sheets-Sheet 1 Ha. I.

v' Q a f @2 //Vl/E/V7'0/? HARRY FFANNEN$TIEHL A TTORNEY Patented July 19, 1932 UNITED: STATES. PATENT OFFICE HARRY PFANNENSTIEHL, OF MOUNTAIN LAKES, NEW JERSEY, "ASSIGNOR TO BELL TELEPHONE LABORATORIES, INCORPORATED, OF NEW YORK, N. Y., A CORPORATION on NEW YORK DRIVING MECHANISM Application. filed June 23, 1928. Serial No. 287,731.

This invention relates to driving mechanisms for linking a prime mover with driven apparatus in situations where at u times it will be necessaryto change the an 5 gular space relation of the driven member with respect to the prime mover. The device was developed for use in motion picture projection apparatus in which the projector head must be arranged to be tilted to a suitm able projecting angle in accordance with the location 'in,.which it is to be used. When the driving motor is mounted on the baseof the machine, it is obvious that the driving linkage must be to some extent adjustable in order to compensate for the relative movement between the projector head and thebase portion. Theinventive idea may be applied to various types of machinery and it is to be understood that the scope of a the invention is to be limited by the claims onl Y Iii providing a driving linkage betweena prime mover and a driven member in which relative motion between the two takes place,

5 the use of universal joints and a telescoping shaft logically suggestsitself and is an arrangement wellv understood in the art. When a universal .jointis used, torque irregularities .are introduced which will be increased i as the angle between the shafts coupled by the universal joint is increased. 7

It is the object of this invention to neutralize the torque irregularities ofuniversal joints in driving systems of the type just discussed. v Y

A feature of the invention is an arrangement in which a driving linkage is provided consisting of a driving shaft having three sections and in which the end sections are coupled to the central sectionby means of twouniversal-joints and in which provision is made to maintain the end sections of said shaft axially parallel regardless of the relative positions in space of the prime mover and driven mechanism.

A further feature'of the invention pro vides means whereby the driving shaft may be clamped. in position with the end-sec.- tions axiallyv parallel in which position the torque irregularities of one universal joint four legs 2 and act to neutralize the torque irregularities of the second universal joint.

A more complete understanding of the invention may be had from the following detailed description, reference being had to the accompanying drawings.

In the drawings, Fig. 1 is a perspective View of a .motion picture projector equipped with sound reproducing devices arrangedfor synchronous operation therewith. The projector embodies a driving connection in accordance with the principles of this invention.

Fig. 2 is a perspective View of the base of the machine on which the motion picture projector may be mounted. This base shows the method of mounting various forms of sound reproducing equipment.

Fig. 3 is a View showing in detail the arrangement whereby the upper gear housing in which the driving link terminates may be rotated and clamped in proper position so that the end sections of the driving shaft may be maintained axially parallel.

Referring now to Fig. 1, a general description .of the apparatus will be given in order that the utility of the driving link may be more apparent. A bed plate 1 is mounted on may be adjusted as to height above the floor by means of clamping saddles 3. A driving motor 4 is mounted on the bed plate and is supplied with power from a cable 5 which terminates in a connection box 6. The motor 4 drives a rearwardly extending shaft which is connected by means of flexible 'oints 7 and 8 to a phonograph turntable 9.

ower is transmitted to the turntable 9 through a mechanical filter of known construction which tends to smooth out torque irregularities in the driving shaft. The turntable 9 is supported bybracket 10 which may be bolted to the bed plate 1 by means of bolts 11, one of which may be seen in Fig. 2. A guard rail 12 is suitably secured to the bracket 10 to protect the turntable 9 from interfer- 9 ence. Astandard 13 extends upwardly from bracket 10and has mounted thereon a base 14 on which is pivoted an arm l5rto one end of which is connected an electrical phonograph reproducer 16. The phonograph equipment just described may be removed by the removal of bolts 11 and disconnection of the shaft to motor 4-. It is, of course, obvious that the connections to the electrical phonograph reproducer must also be disconnected.

The motor 4" at its front end transmits power through a steadying fly. wheel 17 to a of the motor. A third spind1e,.not shown,

forms a horizontal shaft upon which a sprocket'is mounted to drive roller chain 22 7 the top of the magazine which cooperates with the sprocket24 of the friction clutch which drives the shaft on which the film take-up reel may be mounted.

A magazine '27 is provided to house the take-up reel." The position of this magazine may-behest seen in Fig. 'The magazine is providedwitha d0or28which may be opened by means ofa-hand'le 29. A window is provided by means of-which a view of the inter-ior of the magazine may be had when the machine is in motion. The magazine 27 consists'of a rather rugged casting and includes aback plate which terminates at the forward edge in adouble flange extending to either side. One of the flanges forms the forward side of the magazine. The magazine is'bolted to the bedpla'te lat convenientpoints and in combination with the flanges just "described serves as a mounting for other parts 'o'f the apparatus. A' bracliet 31' is bolted to 27' and is provided in its upper forward-portion with suitable trunnions which support the pivoted superstructure or upper base which: carries-'theproj ector head and film sound reproducing equipment. [The upper base consists of a frame with suitable trunnions to cooperate with a bush- ?ing carried by bracket "A. curved operating member 32 "forms "apo'rtion of the upper "base and provides "means whereby 1 the projector *head" may be tiltedfto 'any desired angle. A bar 33"isarranged to slide-through a clampingmeinber 34; suitably trunnioneddn 'the' end'of arm 32. The member 34is'a'rranged'for rotation in its journals to allow 'for angular changes between the bar 33 and ar f 32 when the upper base is raised or lowered. Set screws '35 and 36: serve to clamp the bar in adjusted 1 position with" respect to arm 32. v The lower end of bar 33 is thre'aded into-.a'nut vvhi-ch'may beturnedby nieans of a handwheel37. The handwheel 37 -and=nut 'arefrot'ata'bly"mountedin abloclr'38but are "held against "longitudinal? motion therein.

The block 38" is" suitablytrunnioned to stand "ards '39 which are bolted .to the bed-plate '1. By means of the handwheel' 37 an-ex-act tilt- 'lngangle may be reache d after the upper base i and draws a provided with thatvertic al 21 are rotated upon rotation I has been brought into approximate position by simply lifting it into such approximate position and then clamping it by means of screws 35 and 36. In order to stabilize the machine and prevent any vibration which might occur in case theflmain pivot point became worn a secondary clamping device is provided. This clamping device is arranged to grip a sector A0 which formsa rear wallfor bracket A T-h'andle ilrot'ates a threaded shaft threaded block against one edge ofthe sector 40 to firmly clamp the upper base in -adjusted position.

Continuing-the description of Fig. 2 it will be seen that a support for a pro ector arc lam-p is provided in the reanof the upper base portion. This suppont consists of two tubular memb'ers l2and43 which are mounted in sockets 44 by means of clamping *set screws. "Support and rigidityare2giventothe support for the-lamp by means ofa brace4'5 which is fitted at one end into a socket46 onarm '32. The tubular members 42 and 43 are stiffened and held iii-alignment in the'rear by means of a strap Minter-which they are secured by means of a socket and set screw arrangement. The supports for the' arc lamp housing are adjustably-mounted on rods l-2 and 43' and are shown at-48 and-49. I

The upper base portion-asprovided with compartments50, 5 1 and 52 for housing various parts "of the film sound reproducing equipment.

' The sound reproducing-equipment consists of a constant intensity l'amp; an optical system by means of which a narrow band of light from'said lamp- -is focused -on the 'film as it passes a n aperture plate and a photoelectric :cellwhosecurrentoutputis varied in a'ccordance with the {film density variations. The 'lamp -is housed in compartment 50pand its intensity'inay be regulatedby meansofarheostat 71. Thei'lafmount of c'urrent supplied to the'la'inpm'aylbe'checked by means of a meter 72 mounted on the door of; the compartment.

A glass-door provides access to compartment' 51;"which' houses the lens tube assembly whereby the narrow-band of-light is proj ect- 3 d lover-thefil-m. "This compartment also houses the drivingsprocket for imparting mo- 'tion to -=the film; and various guide rollers. The photoelectric; cell is {housed in compartment 52 whi ch is also provided with a door ffor convenient access thereto. The driving sprocket of {the sound reproducing attachment' is mounted on a shaft-pass; ing thma gn the bushing which forms'the axis on-which the upper base portion may be rotated above {the main' base. T It is' therefore obvious that tilting the i upper base'portion has no e'fl'ect on the drive-don the film sound reproducing equipment since their 1 axes are coincident c p vacuum tubeamplifier'is mounted in=the box 353 which is provided-witha compartment heads is of such a nature that door in which a switch handle 54 appears at a convenient point. A controlling rheostat for the amplifier isshown at 55 and a meter is indicated at 56. This amplifier is housed as a preliminary amplifier to provide amplification for the relatively feeble output of the photoelectric cell. It is necessary to provide this amplifier in order to bring the output of the photoelectric cell up to a point where it is comparable with the output of the phonograph reproducer 16. Electrical connections to the amplifier and sound reproducing equipment are brought to the machine by means of an armored cable containing a number of conductors. This cable is indicated at 57.

A pedal 58 is provided to control the starting and stopping of the machine. Lifting the pedal releases a brake shoe which cooperates with flywheel 17 Fig. 1, and at the same time operates an electric switch to close the circuits of motor 4. Depression of the pedal opens the circuit of motor 4 and continued movement, downward applies the brake shoe to the outer surface of flywheel 17 to quickly slow down and stop the machine.

Referring now to Fig. 1 flywheel 81 is secured to the shaft which drives the feed sprocket of the film sound reproducing device. This flywheel is driven through suitably damped springs by means of a spider which in turn is driven from a bevel gear arrangement actuated by vertical shaft 59. The shaftv 59 is connected to vertical spindle 21 by means of suitable coupling members 60 and 61.

Fig. 1 shows a standard projector head mounted on the upper base portion. .This projector head forms no part of the invention and will not be described in detail. It should be noted, however, that by means of suitable adapter plates any standard make of projector head may be secured to the upper base portion.

The driving mechanism for the projector it may be adjusted to operate properly irrespective of the type of head used or of the tilting angle to which the upper base is set. A case 90 forms a housing for bevel gears one of which is secured to the main driving shaft of the projector head. The housing 90 is provided with an arm 91 which cooperates with a slotted link 62 suitably secured to the main frame to form a clamping device for maintaining the gear housing in adjusted position. The vertical shaft 63 which drives the bevel gears is connected with the vertical driving spindle 20 by means of two universal joints 64 and 65. These universal jointsmay be of any well known construction. In order to allow angular motion of the upper base portion or to compensate for variations in the location of the driving shaft of various types of proj ector heads the central portion 66 of the driving link is made extendible, and may telescope upon itself. As seen in Fig. 1 the shaft 66 until the end sections of the comprises an outer sleeve portion and an illner driving portion each square in section. Since the two portions of the shaft are square in section they will rotate one regardless of the extent to which the shaft is extended.

As was previously pointed out the purpose of making the upper gear-housing 90 pivotable about the axis of the driving shaft for the projector is to enable the end sections of the driving linkage to be maintained axially parallel so that the torque irregularities of one universal joint will neutralize the torque irregularities of the other. After the machine is set up and tilted to the desired angle the gear housing 90 is rotated about its axis driving linkage are parallel. The housing is then clamped in adjusted position by means of set screws 67 and 68. The set screw 67 is threaded into arm 91and set screw 68 is threaded into a convenient portion of the frame of the lower ase portion. Inspection and adjustment of the upper bevel gears may be made by removing the housing cover 69 secured to housing 90 by means of screws 7 0.

What is claimed is:

1. A driving shaft comprising a middle and two end sections, two universal joints connecting the middle section with the end sections, mechanism driven from one of said end sections and a prime mover connected to the other end section, means to change the angular space relation between said prime mover and said driven mechanism, and an adjustable compensating device operable to maintain said end sections in axially parallel relation for any selected space relation of said prime mover and said driven mechanism.

. A prime mover, a driven mechanism, a

driving shaft interconnecting said prime mover and driven mechanism, said shaft comprising a midde and two end sections and two universal joints interconnecting said sections, and means to mutually neutralize torque irregularities due to universal joint action, said means including an adjustable maintains the end parallel regardless of the angular space relation of said prime 7 mover and said driven mechanism.

3. A driving shaft comprising a middle and two end sections, two universal joints connecting said middle section with said end sections, mechanism driven from one of said end sections and a prime the other end section,

driven mechanism, a compensating device end sections in axially parallel relation, and means to clamp said compensating device in a desired position.

4. A driving shaft comprising a middle and two end sections, two universal joints connecting the middle section with the end secmover connected to operable to maintain said its 4: leeseefi,

tipns,;mechanism driszen from one of sand end seetiens'and a'piinl e mover connected to the bthejr rend 'seetion,,means to Change the angu l ai' spnjce relation between said prime mover and Said driven mechanism, said middle sec- {oion Of said shaft being telescopic to permit said change and a compensating device adjnstabletdmaintain said end sections in axfilly parallel relation. V 0 {In Witness whereof I hereunto subscribe my narneth'is 22d day of June, 1928. I

l HARRY BFANNENSTIEHL. 

